From mboxrd@z Thu Jan 1 00:00:00 1970 From: Douglas Gilbert Subject: Re: sense buffer length for REQUEST SENSE? Date: Sat, 27 Jul 2002 00:47:17 -0400 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <3D4225D5.9A8ED692@torque.net> References: <3D420D77.A4633D9C@splentec.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: List-Id: linux-scsi@vger.kernel.org To: Luben Tuikov Cc: linux-scsi Luben Tuikov wrote: > > The sense buffer size is 64 bytes. I can plead guilty to that. A finger in the air trade off between the standard ** and reality. It previously was 16 bytes (changed in lk 2.3 I think). At 64 bytes it matches the size of the Scsi_Cmnd::sense_buffer array (and Scsi_Request::sr_sense_buffer). > According to SAM-3, to make sure that that an application SAM-3 is new (it branched off recently from SAM-2) and adds SAS to its protocol tables. SAS is SCSI over Serial ATA type infrastructure ... SAS may displace Ultra 640. > client has gotten all the sense data the sense buffer > should be 252 bytes. Yes I can see that number in SPC-3. Has anyone every seen an actual REQUEST SENSE response (sense buffer) anywhere near that size? The new "descriptor" sense data format should further reduce the size requirement. > How safe am I to actually set the allocation length > to 252 bytes? (in terms of borken hardware devices, etc.) Following the lead from 36 byte INQUIRYs, what does Windows do? BTW I have not seen a report of the current 64 byte allocation length causing a problem. ** SCSI-2 said 18 bytes or greater and now SPC-3 says at least 252 bytes. Doug Gilbert